These days, despite the development of diagnosis and treatment techniques for cancer patients, the number of patients who suffer pain due to spreading of cancer to the bone increases. In America alone, 1.2 millions of people are newly diagnosed with cancer every year, and 50% of these develop bone metastases according to statistics. Most cancers tend to spread to the bone, and approximately 20 to 80% of bone metastases have been reported according to the types of the cancers.
The cancer cells spreading to the bone cause bone melting and weakening, thus cause pathologic fracture or impending fracture, which is accompanied with severe pain and serious functional disabilities. Most bone metastases have multiple occurrences. Although advanced cancer patients are in need of surgical operation, it certainly is the great burden as well as high risk to both the patient and the medical professionals, as the surgical procedure involves incision of skin and muscles of the patient who already has unstable general condition or in need of on-going chemotherapy.
While the aged people take up large portion of the cancer patient population, the aged patients are more likely to develop osteoporotic bone fractures due to occurrence of osteoporosis generated in the process of cancer treatment. Such condition has high risk of developing into complications such as non-union of the fracture sites, weakness of general condition or loss of limb functions.
Therefore, efforts are necessary, to provide a surgical treatment of the involved bone that can be conducted in a simple and efficient manner, while preserving the general condition as much as possible, and without causing complications, particularly for the senile patients or advanced cancer patients.
The main treatment generally involves invasive surgery which includes incising skin and muscles to form bony window on the bone, curettage of tumor mass, reinforcing with bone cement, and using intramedullary nail or plate, tumor prosthesis or joint replacement arthroplasty.
A method for facilitating bone-union to treat the osteoporotic bone fracture generally involves fixing the fracture site with intramedullary nail or plate, defining a hole in the bone, inserting an injector, and introducing osteoinductive or osteoconductive bone substitutes therethrough. Materials for direct coating to promote bony incorporation on the stem of prosthesis and to prevent bone resorption have been used. In other words, the implant is required to play a role of drug-deliverer, as well as bone fixer.
Although percutaneous bone cement injection is used for the osteoporotic spinal compression fracture or metastatic bone cancer, it is difficult to prevent pathologic fracture particularly at the long bone of limb, in the absence of the internal fixation of metal implant. However, when the bone metastasis is accompanied with osteoporosis or progressed bone fracture, the internal metal fixator easily loosens out of the bone due to weakened bone, which is problematic. Accordingly, improved bone fixation method is necessary, which plays a role of not only the internal metal fixator, but also treatment agent injector.
Accordingly, an effective bone augmentation and stabilization surgical method is necessary, which can minimize surgical risks of the patients which may already have deteriorated general condition and also effectively reinforce weakening bones.